How to use Google Chart with data from a csv

The jquery-csv library provides the ability to translate a string of csv into an array to be used by google.visualization.arrayToDataTable() (their example here). To make this work, add jquery.csv.js to your server (in the example below I assume it is in the same folder as your HTML) and link to it in your <head>. The following is a simple script you can add to your <head> to get started. I assume a scatter chart, but this process works for any of the charts here. You will also need a <div> with id="chart" for this to work.

// load the visualization library from Google and set a listener
google.load("visualization", "1", {packages:["corechart"]});
google.setOnLoadCallback(drawChart);

// this has to be a global function
function drawChart() {
   // grab the CSV
   $.get("example.csv", function(csvString) {
      // transform the CSV string into a 2-dimensional array
      var arrayData = $.csv.toArrays(csvString, {onParseValue: $.csv.hooks.castToScalar});

      // this new DataTable object holds all the data
      var data = new google.visualization.arrayToDataTable(arrayData);

      // this view can select a subset of the data at a time
      var view = new google.visualization.DataView(data);
      view.setColumns([0,1]);

     // set chart options
     var options = {
        title: "A Chart from a CSV!",
        hAxis: {title: data.getColumnLabel(0), minValue: data.getColumnRange(0).min, maxValue: data.getColumnRange(0).max},
        vAxis: {title: data.getColumnLabel(1), minValue: data.getColumnRange(1).min, maxValue: data.getColumnRange(1).max},
        legend: 'none'
     };

     // create the chart object and draw it
     var chart = new google.visualization.ScatterChart(document.getElementById('chart'));
     chart.draw(view, options);
  });
}

I have been searching for a while, and found the solution on a Google group discussion. https://groups.google.com/forum/#!topic/google-visualization-api/cnXYDr411tQ

I have tried it, and it works!

In this case, we have to specify the header types of our csv file.

var queryOptions = {
    csvColumns: ['number', 'number', 'number' /* Or whatever the columns in the CSV file are */],
    csvHasHeader: true /* This should be false if your CSV file doesn't have a header */
}
/* csvUrl is the path to your csv */    
var query = new google.visualization.Query(csvUrl, queryOptions);
query.send(handleQueryResponse);

function handleQueryResponse(response) {

    if (response.isError()) {
        alert('Error in query: ' + response.getMessage() + ' ' + response.getDetailedMessage());
        return;
    }

    var data = response.getDataTable();

    var chart = new google.visualization.ColumnChart(document.getElementById('your div'));
    // Draw your chart with the data table here.
    // chart.draw(view, queryOptions);
}

Tags:

Javascript

Csv

Google Visualization

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